reef rock
4.According to the differences of sedimentary facies and environment, the source rock are divided into four types such as lime-mud reef in platform margin, platform inner sag, deep-water flat slope or continental shelf, abyssal basin, the lime-mud reef type is distributed in platform margin of Upper Ordovician, the remained three types are widely distributed in Cambrian-Ordovician system.
5.Based on available data, the study on regional structure, sedimentary reservoir and source rock characteristics shows that the basins in South China Sea had experienced sedimentary evolution in faulting period and depression period, deposited thick Cenozoic formation, upwardly developed alluvial fan facies, river-lake facies→coastal swamp facies→coastal facies, neritic facies and bathyal deposit system, regionally had 3 source rocks of Eocene, Oligocene and Miocene, 3 reservoirs of pre-Cenozoic basement buried bill, Oligocene sandstone and Miocene reef, with Pliocene and Pleistocene neritic facies and bathyal shale as regional caprock.
